Insulation



INSULATION s. F. TCRsTENssoN Filed March 19, 1957 l O@ x.

Aug 30, 193s.

INVENTOR. BY X7, )rd

j. ATTORNEY.

Patented Aug. 30, 1938 UNITED STAT-l:

PATENT OFFICE INSULATION Sture Folke Torstensson, Stockholm, Sweden Application March 19,

4 claims.

new and improvedmethod of producing insulation of this type.

I provide a casing which may be of thin sheet metal and fill this casing with a sludge comprising a finely divided material mixed with a suitable liquid and then remove the liquid, as by evaporation, leaving the finely divided material in place in the casing. The casing is then evacuated and sealed.

My invention, together with the objects and ad-v vantages thereof, will be more fully understood upon reference to the following description taken in connection with the accompanying drawing :0 forming'part of this specification and of which:

Fig. 1 shows schematically, with parts in vertical section, an apparatus for carrying out the vmethod of my invention;

Fig. 2 is a detail sectional view illustrating a closure for the filling opening of the insulation casing shown in Fig. 1; and

Fig. 3 is a detail sectional view showing the sealing connection for evacuating the insulation casing shown in Fig. 1.

Referring to Fig. 1 of the drawing, a thermal insulating element I0 comprises an outer sheet metal wall II and an inner sheet metal wall I2 forming therebetween a space I3 of a desired thickness. The edges of the metal shells II and I2 are connected by a peripheral flanged member I8 and a strip I5 of sheet metal of relatively poor thermal conductivity to reduce'heat transfer between the inner and outer shells. l

The outer shell II is provided with a suitable filling opening I6 and an evacuation opening I1'. As more clearly seen in Fig. 3, the evacuation opening I1 is provided in a depressed portion I8 of the outer shell II, and one end of a sealing tube I9 communicates with the opening I1 and is attached to the shell II around the openingall. Suitable coarse granulated material is held in place around the opening I1 by means of a screen 2|. The filling opening I6 is also provided in a slight depression in the'outer shell II and has an upturned peripheral fiange as seen in Fig. 2. In accordance with my Invention I introduce into the space I3 a mixture of a finely 4divided material such assiliceous guhr and water or alcohol or other suitable liquid. l The mixture, which may be referred to as a sludge, is contained 1937, serial No. 131,881;

Germany March 25 1936 (Cl. 'l2-416) in a tank 22 having a discharge funnel 23 con-4 trolled by a valve 24. The tank 22 may be provided with a suitable scale or indicator 25 to show the quantity of sludge discharged therefrom upon` opening of v'alve 24. The insulating element I0 is advantageously placed on aspringboard 26 below the funnel 23 so that the lower end of the funnel extends into the filling opening I6'. On the springboard 26 there is also mounted a motor 21 having a biased or eccentric flywheel 28. The tank 22 may be nseparately mounted or Vit may' also be mounted on the springboardy 26. The tank 22 is filled with sludge andthe valve 24 opened to permit the sludge to descend through the funnel 23, through the filling opening I6, and into the space between the walls II and I2. During this procedure the motor 21 is operated to cause shaking of the insulating element to cause the sludge to be evenly deposited throughout the space I3. When the required amount of sludge has been deposited in the space lI3 to completely ll the same, the funnel 23 is raised out of the filling opening I6 and the latter closed and sealed by a cap 29 having upturne`d flanges which are welded to the anges around the filling opening I6.

The evacuation tube I9 is next connected to l a liquid pump .which withdraws liquid from the eifect complete removal of moisture, the insulating element I8 is heated in an ,oveniwhile the evacuation tube I9 is connected to a vapor pump so that liquid is vaporized in the space I3 and drawn off by the pump. By means of the evacuation tube I9, an increasingly finer vacuum is drawn in the space I3 until the pressure therein! spacevll, leaving the solid matter in place.` To v has been reduced to between 0.1 and 2 mm. Hg. i

Thereupon the depression I8 which may then be'iilled with a sealing compound such as pitch to protect the tube ISL The amount of vacuum space with respect to the solid material may be determined by the oproportion of siliceous guhr or the like mixed with water to form the sludge. words. the heavier the sludge the greater the amount of space I3 occupied by solid material, and vice versa. Since the porous solid material in the space I3 acts to support the walls II and I2 against external pressure, these walls are advantageously made very thin, and if very thin `walls are provided, it will be necessary to use a. suitable supporting structure for the element I0 during the filling process described above.

I claim:

the tube I9 is-sealed off and bent into I In other 1. The method of producing thermal insulation 3. A method as set Iorth in claim 1 in which y and nnely divided solid material into a. hollow wall structure.' removing the liquid, leaving the solid v material in place in thewall structure, evacuating the hollow wall structure, and hermeticaliy sealing the same.

-2. A method as set forth in claim 1 in which the hollow wall structure is agitated during the step of lling with the mixture oi' liquid and solid material.

the amount of space between the solid material in the insulation product is determined by the proportion of liquid in the lling mixture.

4. A method as set forth in claim l in which the 5 liquid is removed by evaporation thereof and withdrawal of the vapor.

STURE FOLKE TORSTENSSON. 

